Method of packaging



June. 30, 1970 A. s. BALOCCA METHOD OF PACKAGING Filed April 18. 1968INVENTOR.

United States Patent 3,517,475 METHOD OF PACKAGING Alfred EdwardBalocca, Wheaton, 11]., assignor to American Can Company, New York,N.Y., a corporation of New Jersey Filed Apr. 18, 1968, Ser. No. 722,352Int. Cl. B65b 1/24, 31/02 US. C]. 53-22 Claims ABSTRACT OF THEDISCLOSURE In order to prevent paneling or body-wall deformation of acan or like container which is subjected to reduced pressure or vacuumconditions, or to prevent undesired movement of the product Within thecontainer, :1 portion of the can end closure is reshaped to greatlyreduce the internal volume of the can after the latter has been sealedwith the product therein. The reshaping is facilitated by providing anannular peripheral fold in the end closure whereby mechanical pressuremay be readily applied to the end closure to depress a major portion ofthe latter into the can body as the told is uncollapsed uniformly andevenly to thereby provide a finished package of commercially acceptableappearance.

BACKGROUND OF THE INVENTION This invention relates to a method ofpackaging products wherein a container is reshaped after it is sealed togreatly reduce the internal volume of the package.

Various food products, such as coffee and non-carbonated beverages, arefrequently vacuum-packed in cans. To prevent paneling or body-walldeformation due to atmospheric pressure, it has heretofore been commonto form the can of a heavy-gauge metal. This, of course, results inadded costs. Another expedient to prevent bodywall collapse, but whichpermits the use of a relatively light-gauge metal, has been to providefor reshaping of the can after it is packed to reduce the internalvolume thereof so that the product supports or tends to support the bodyof the can. In this latter system, the product is placed within a can, avacuum is applied to the can and the product to remove the major portionof the air from the can, the can is then sealed while under vacuum,after which the can is reshaped to reduce the volume thereof. Thisreshaping may be done mechanically, or may, if the can end be suitablyprofiled to permit flexing, be effected automatically by the imbalanceof pressure when the vacuumized can is exposed to atmospheric pressure.The extent of reshaping may be such that the product is forced intocompressive engagement with the can body so as to form a support for thecan body and prevent paneling thereof.

Paneling or body-wall deformation also tends to occur under othercircumstances. For example, after filling and sealing containers made ofnon-rigid materials (e.g. thermoplastic) with certain types of products(e.g. motor oil, paint), it has been found that the container side wallstend to panel or become deformed when the container has been stored fora period of time. This deformation or paneling results from a reductionof the pressure within the interior of the container. After thecontainer has been filled and sealed, a small amount of air generallyremains trapped within the headspace of the container. Upon beingstored, the contents of the container may chemically react with orabsorb a component, usually the oxygen, of this residual air. Suchreactions cause the total pressure within the container to drop and, asa result, the side Wall of the container will flex inward or panel dueto atmospheric pressure in order to compensate for this internalpressure drop. When this condition occurs, the container frequentlyassumes an undesirably distorted appearance and sometimes deforms tosuch extent that it will not adequately support another container thatmay be stacked on top of it. In some cases, the container may be filledwith a heated product which reduces in volume upon subsequent coolingand which thereby tends to reduce the internal pressure in the sealedcontainer and thus produces deformation of the container body.

According to the present invention, reshaping of the container, after ithas been packed and sealed, is facilitated by providing a folded portionon an end closure, whereby mechanical pressure may be readily applied tothe end closure to depress the latter into the container body as thefolded portion is uncollapsed to provide the additional material neededto make the depression. The folded portion is preferably located closelyadjacent the periphery of the end closure so that when it is unfolded,maximum displacement of the closure into the container body is obtained.

SUMMARY OF THE INVENTION In a method of packaging a product into a canor like container, 2. product is placed into the can and an end closureis placed thereon and suitably sealed to the can body. To prevent orminimize paneling or body-wall deformation of the can, the internalvolume of the can is reduced by reshaping the end closure after thelatter has been sealed to the can body. In order to facilitate suchreshaping, the end closure, before it is placed on the can, has aportion folded over on itself so that, after the end closure is sealedin place on the can body, mechanical pressure may be applied to the endclosure to effect a fully controlled and uniform uncollapse of the fold,thereby to depress and dispose the major portion of the end closure intothe can body. In some cases, the volume of the can may be reduced to theextent that the product is forced outwardly into compressive engagementwith the can body so as to form a support therefor. In other cases, aslight pressure above atmospheric pressure may be obtained in thecontainer to retard or prevent paneling.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of acontainer having a top end closure with a collapsed fold.

FIG. 2 is a partial sectional view taken substantially along the line2-2 of FIG. 1 and also showing a plunger used to uncollapse the top endclosure fold.

FIG. 3 is a partial sectional view similar to FIG. 2. showing the endpanel after the fold has been uncollapsed.

FIGv 4 is a partial sectional view of various die parts for making afold in the end closure in a position before the fold is made.

FIG. 5 is similar to FIG. 4 but shows the position of the die partsafter the fold has been made.

DESCRIPTION OF THE PREFERRED EMBODIMENT As a preferred or exemplaryembodiment of the instant invention, FIG. 1 illustrates a container,generally designated 10, having a tubular body 12. An upper end closure14 and a lower end closure 16 are secured to the ends of the body 12 inany suitable manner such as well-known doubleseams 18, 20. The bottomclosure 16 may be of conventional, well-known construction or may be thesame as the top closure 14 to be described more fully hereinafter. Inthe illustrated embodiment, the container 10 is made of sheet metal(e.g. tin plate, aluminum, tin free steel, etc.). Under suchcircumstances, the body 12 usually is made from a flat blank which isformed into tubular configuration and its marginal edges joined into alongitudinal extending soldered or cemented side seam 22.

Can bodies, as described above, are well-known in the art and furtherdescription thereof is deemed unnecessary. It is to be understood,however, that it is within the purview of the instant invention to havethe body 12 made from other materials such as thermoplastic resins (e.g.polyethylene, polypropylene, etc.), or by other methods such as drawingand ironing, impact extrusion, injection molding, and thermoforming. Insome of these other procedures, such as thermoforming in the case wherethe container body is made of a thermoplastic resin, the body will beseamless, thereby obviating the presence of the side seam 22. Also, thebottom closure of the container will be integral with and formed of thesame material as the container body, thereby obviating the doubleseam20.

The upper end closure 14, prior to being collapsed and as shown in FIG.2, includes a substantially horizontally extending central panel 24which is recessed within the body 12 and which extends over and coversthe major portion of the open end of the container body 12. At itsperiphery, the panel 24 is bent back upon itself inwardly toward itscenter and then again outwardly toward the body 12 to form an annularfold 2 6. Thus, the annular fold 26 is composed of three layers of metalin contiguous overlying relation and in contiguous relation with theperiphery of the panel 24. It is to be understood that other foldingconfigurations can be used and are, therefore, in the purview of theinstant invention. To facilitate double-seaming, the upper surface ofthe fold 26 is substantially on the same level as the lowermost edge ofthe doubleseam 18. The fold 26 merges with an upward extendingcountersink wall 28 which, in turn, merges with a closure flange 30which is interfolded with a peripheral flange 32 on the body 12 in awell-known manner to form the doubleseam 18.

The fold 26 is made in the end closure 14 prior to the securement of thelatter to the container body 12. Thus, the end closure 14 is initiallyformed into the configuration shown in FIG. 4, wherein the closureflange 30 extends in a substantially horizontal direction on a planespaced from the horizontal plane at which the central panel 24substantially lies with the countersink wall 28 disposed therebetween.The countersink wall 28 is joined to an inwardly and downwardlyextending annular step 34 which is, in turn, joined to a generallyvertical annular wall 36 extending generally perpendicularly from thepanel 24. By using suitable dies, as illustrated schematically in FIGS.4 and 5, the step 34 and vertical wall 36 are collapsed to form the fold26.

The dies for forming the fold 2-6 consist of a generally cylindricalsupport tool 38 disposed within the bore of and moveable axially (asindicated by the arrow 40 in FIG. 4) relative to an upper support ring42, and a generally cylindrical collapsing tool 44 also disposed withinthe bore of and moveable axially relative to a lower support ring 46.Initially, the die parts are axially separated and the end closure 14,having the configuration shown in FIG. 4, is located on the lowersupport ring 46. Thereafter, the upper support ring 42 is moved axiallyto clamp the flange 30 and countersink wall 28 between the two supportrings 42 and 46 as shown in FIG. 4. Thereafter, the collapsing tool 44and support tool 38, having the panel 24 sandwiched therebetween, aresimultaneously moved axially relative to the support rings 42 and 46,which remain fixed, from the FIG. 4 to the FIG. position to reshape thestep 34 and annular wall 36 to form the fold 26. The support tool 40precludes inward collapse of the vertical wall 36 of the end panel 14while a cavity 48 formed by the die parts outwardly of the verticalportion 36 is provided to accommodate the fold 26 as it is being formed.In this regard, it will be observed that the vertical wall 36 of the endclosure 14 is the weakest unsupported section within the cavity 48formed between the die parts so that as mechanical pressure is appliedto the panel 24 by the collapsing tool 44, the latter is effective tocollapse the vertical portion 36 outwardly (as indicated in broken linesin FIG. 4) within the die cavity 48. The collapsing tool 44 and supporttool 40 are brought to the position shown in FIG. 5 wherein the fold 26has been completely formed within the die cavity 48. Thereafter, the dieparts are axially separated for removal of the end closure 14 therefrom.Prior to the application of the closure 14 to the body 12, its flange 30is edge curled and lined with a suitable compound.

According to one embodiment of the invention, after the container 12 hasbeen filled with a product P and prior to sealing of the end closure 14to the body 12, the container and product are disposed in a vacuumchamber and the end closure 14 is set in place on the can body inclosely spaced relationship above the contents P. The desired vacuum isobtained in the container and the end closure 14 is sealed to the body12 by a conventional can-closing mechanism (not shown) which forms thedoubleseam 18.

The container is then located beneath a mechanical plunger assembly 50-(see FIG. 2) which includes a vertical, reciprocably mounted shaft 52on the lower end of which is secured a plunger 54. The latter is of alesser diameter than the container body 12 and is intended to engageonly the upper surface of the end closure panel 24 radially inwardlydisposed of the fold 2-6. The plunger assembly 50 is operable touncollapse the fold 26 and depress the end panel 24 to dispose the majorportion of the end closure 14 into the can body (see FIG. 3). As aresult, the internal volume of the container is reduced so that the headspace in the container is substantially eliminated. In some cases, theinwardly offset panel of the end closure can actually be moved intocontact with the container contents to press the latter against the bodyto support the body wall and prevent collapse thereof, or, if desired,when the contents are solid, to clamp the contents between the oppositeends of the can 10 to thereby prevent undesired, and possiblydestructive, movement of the contents within the can.

If the product in the container is of a granular type (e.g. coffee), theproduct may be compressed and compacted as the depressed panel reachesits full, uncollapsed disposition shown in FIG. 3. When this occurs, alighter body material may be used in the construction of the containerthan is normally used in containers of this type when the product isvacuum packed without subsequent reshaping of the container.

In the case of products which are packed under atmospheric conditions,an air-filled headspace frequently exists between the surface of thefluid and the internal surface of the end closure 14 due to the factthat it is not practical or economically feasible to fill the containercompletely to eliminate all residual air space or voids. It has beenfound that constituents of certain fluid products (e.g. motor oil) mayreact chemically with this air within the container in the normal courseof storing such a filled container. Such chemical reactions of the fluidresult in the reduction of internal pressure in the container in thatthe reactions use up the oxygen in the head space, and the partialpressure, previously created by the oxygen, is no longer present and,consequently, the internal pressure in the container will be reduced. Asimilar result of reduced total internal pressure would prevail forchemical reactions between the fluid and any of the other constituentsand/ or components of the residual space. Further, after the containeris initially filled with a heated product (e.g. motor oil which has beenheated to make it less viscous for filling), its subsequent cooling willtend to cause a reduction in the internal pressure. With reduction ofinternal pressure, the atmosphere or surrounding environment acts uponthe com tainer, tending to cause the side wall of the container tobuckle or panel.

According to the present invention, the end panel 14 is depressed intothe container to the extent of imposing a pressure, above atmospheric,within the container, Thus, by reducing the internal volume of thecontainer after sealing, thereby to take up the head space and impose apositive internal pressure, slightly above atmospheric, paneling isretarded or prevented.

In some instances, as where the product within the container is solid,the controlled collapse of the fold 26 may be utilized to move the panel24 into contact with the product to clamp it against the opposite endclosure in order to prevent undesired, and perhaps destructive, shakingmovement of the product within the container.

It will be understood, of course, that collapsed ends of the type hereindescribed may be used on both ends of the body 12 in order to produce adouble reduction of the volume within the can.

It is thought that the invention and many of its attendant advantageswill \be understood from the foregoing description and it will beapparent that various changes may be made in the steps of the methoddescribed and their order of accomplishment without departing from thespirit and scope of the invention or sacrificing all of its materialadvantages, the method hereinbefore described being merely a preferredembodiment thereof.

Iclaim:

1. The method of packaging a product into a container, comprising thesteps of:

providing an empty container body and an end closure for said body,

folding a portion of said end closure over on itself,

placing the product in the body,

placing said end closure on said body,

sealing said end closure to the body, and

uncollapsing said fold by appling pressure to the end closure, therebyto depress a portion of the latter into the container body.

2. The method of packaging according to claim 1 wherein said toldextends annularly, and said step of applying pressure to the containercomprises applying mechanical pressure to said end closure at a locationadjacent said annular fold.

3. The method of packaging according to claim 1 wherein said step offorming a fold in said end closure comprises applying a force to presscontiguous parts of the end closure into overlapping and abuttingengagement.

4. The method of packaging according to claim 3 further comprising thestep of forming the fold into three overlapping and abutting layers.

5. The method of packaging according to claim 1 wherein said end closurehas a closure flange and a substantially flat central panel with acountersink wall disposed therebetween, said step of folding a portionof said end closure comprises forming a generally sinuously configuredsection between said central panel and said countersink wall.

6. The method of packaging according to claim 1 wherein said end closureis sealed to the container body under atmospheric conditions.

7. The method of packaging according to claim 1 wherein said end closureis depressed into the container body sufliciently to impose a pressureabove atmospheric Within the sealed container.

8. The method of packaging according to claim 1 wherein said end closureis sealed to the container body under vacuum conditions, said endclosure being depressed into the container body to the extent that theproduct is forced into compressive engagement with the container body.

9. The method of packaging according to claim 1 wherein a head space ispresent in the container between said product and end closure after thelatter has been scaled to the container body, said end closure beingdepressed into the container body to the extent that said head space issubstantially eliminated.

10. The method according to claim 1 wherein said fold has a sinuouslyconfigured cross section, said fold being uncollapsed by applyingmechanical pressure to said end closure in an axial direction.

References Cited UNITED STATES PATENTS 3,056,244 10/1962 Bartels 53-22 X3,117,873 1/1964 Bartels et a1 53-22 X THERON E. CONDON, PrimaryExaminer R. L. SPRUILL, Assistant Examiner US. Cl. X.R.

